During a normal cycle of heart contraction (systole), when the left ventricle contracts, the mitral valve acts as a check valve to prevent flow of oxygenated blood back into the left atrium. Oxygenated blood can be pumped into the aorta through the aortic valve. Regurgitation of the mitral valve can significantly decrease the pumping efficiency of the heart, placing the patient at risk of severe, progressive heart failure. Mitral valve regurgitation can be characterized by retrograde flow from the left ventricle of a heart through an incompetent mitral valve into the left atrium. Mitral valve regurgitation can result from a number of mechanical defects. For example, leaflets, chordae tendineae coupled to the leaflets, or the papillary muscles of the mitral valve may be damaged or otherwise dysfunctional. In at least some instances, the mitral valve's annulus supporting the leaflets may be damaged, dilated, or weakened, thereby limiting the ability of the mitral valve to close adequately against the high pressures of the left ventricle.
Mitral valve replacement is often performed to treat mitral valves. Unfortunately, mitral valve replacement poses unique anatomical obstacles, rendering mitral valve replacement procedures risky and more challenging than other types of valve replacements, such as aortic valve replacement. This is because the mitral valve annulus often has a non-circular D shape or kidney like shape, with a non-planar geometry. It may be difficult to properly position a prosthetic mitral valve within the native mitral valve. If the prosthetic mitral valve is at an improper orientation, blood may flow through gaps between the prosthetic mitral valve and the leaflets and/or annulus of the native mitral valve. Percutaneous catheters can be used to deliver prosthetic valves. Unfortunately, self-expanding prosthetic mitral valves can deploy in an uncontrolled manner due to axial jumping or self-ejection. The uncontrolled deployment of prosthetic mitral valves can result in improper positioning of the prosthetic mitral valve resulting in leakage, migration of the prosthetic mitral valve, and other unwanted problems.